Conservative Christian groups in the Philippines have marched near a shopping mall to demand the cancellation of Lady Gaga's two concerts, saying her songs carried "demonic" undertones.

The protests in the heavily Catholic Philippines followed a decision this week by authorities in Indonesia, a secular state but with the world's largest Muslim population, to refuse her a permit to perform in Jakarta next month.

In Manila at the weekend, dozens of anti-riot police stopped hundreds of protesters from two groups from marching to the concert venue with placards reading "Stop Lady Gaga concert" and "Don't support Lady Gaga".

A much larger group prayed and sang hymns as the performer arrived in the evening in the city. Protesters planned to hold a prayer vigil on Sunday ahead of the performances.

Concert organizers said they were aware of no plans to cancel the concerts, with fans prepared to pay up to 15,000 pesos for tickets - in a country where the average monthly wage is about 10,000 pesos.

"We're hoping that if they will continue the concert, they should tone it down," Benny Abanted, a Christian pastor, told reporters. "She should not sing songs that could offend our spiritual senses or wear bikinis in front of the crowd."

Other group members described her songs as "grossly blasphemous, immoral, lewd and carrying demonic and occultist undertones".

Protests in South Korea, which has Asia's second largest population of Christians after the Philippines, prompted authorities to bar under-18s from Lady Gaga's concert.